With the launch of the next generation Porsche 911 this week, Top Gear has taken a look back in time at one of history's most iconic sports cars. While many are quick to point out that every Porsche looks the same (okay, they pretty much do), each era of the 911's 55-year history undoubtedly has its defining design cues. Scroll through the decades of a model that has rolled off the production line over 1,000,000 times.